[llvm-commits] CVS: llvm/lib/Target/TargetData.cpp

[Reid Spencer]

Changes in directory llvm/lib/Target:

TargetData.cpp updated: 1.101 -> 1.102
---
Log message:

Implement support for non-standard integer bit widths of any size. The 
rules alignment is to pick the alignment that corresponds to the smallest 
specified alignment that is larger than the bit width of the type or the 
largest specified integer alignment if none are larger than the bitwidth
of the type. For the byte size, the size returned is the next larger 
multiple of the alignment for that type (using the above rule). This patch
also changes bit widths from "short" to "uint32_t" to ensure there are 
enough bits to specify any bit width that LLVM can handle (currently 2^23);
16-bits isn't enough.


---
Diffs of the changes:  (+33 -10)

 TargetData.cpp |   43 +++++++++++++++++++++++++++++++++----------
 1 files changed, 33 insertions(+), 10 deletions(-)


Index: llvm/lib/Target/TargetData.cpp
diff -u llvm/lib/Target/TargetData.cpp:1.101 llvm/lib/Target/TargetData.cpp:1.102
--- llvm/lib/Target/TargetData.cpp:1.101	Fri Feb 16 18:41:42 2007
+++ llvm/lib/Target/TargetData.cpp	Mon Feb 19 16:35:00 2007
@@ -94,7 +94,7 @@
 
 TargetAlignElem
 TargetAlignElem::get(AlignTypeEnum align_type, unsigned char abi_align,
-                     unsigned char pref_align, short bit_width) {
+                     unsigned char pref_align, uint32_t bit_width) {
   TargetAlignElem retval;
   retval.AlignType = align_type;
   retval.ABIAlign = abi_align;
@@ -188,7 +188,7 @@
     std::string arg0 = getToken(token, ":");
     const char *p = arg0.c_str();
     AlignTypeEnum align_type;
-    short size;
+    uint32_t size;
     unsigned char abi_align;
     unsigned char pref_align;
 
@@ -213,7 +213,7 @@
       align_type = (*p == 'i' ? INTEGER_ALIGN :
                     (*p == 'f' ? FLOAT_ALIGN :
                      (*p == 'v' ? VECTOR_ALIGN : AGGREGATE_ALIGN)));
-      size = (short) atoi(++p);
+      size = (uint32_t) atoi(++p);
       abi_align = atoi(getToken(token, ":").c_str()) / 8;
       pref_align = atoi(getToken(token, ":").c_str()) / 8;
       if (pref_align == 0)
@@ -233,7 +233,7 @@
 
 void
 TargetData::setAlignment(AlignTypeEnum align_type, unsigned char abi_align,
-                         unsigned char pref_align, short bit_width) {
+                         unsigned char pref_align, uint32_t bit_width) {
   for (unsigned i = 0, e = Alignments.size(); i != e; ++i) {
     if (Alignments[i].AlignType == align_type &&
         Alignments[i].TypeBitWidth == bit_width) {
@@ -250,10 +250,11 @@
 
 /// getAlignmentInfo - Return the alignment (either ABI if ABIInfo = true or 
 /// preferred if ABIInfo = false) the target wants for the specified datatype.
-unsigned TargetData::getAlignmentInfo(AlignTypeEnum AlignType, short BitWidth,
-                                      bool ABIInfo) const {
+unsigned TargetData::getAlignmentInfo(AlignTypeEnum AlignType, 
+                                      uint32_t BitWidth, bool ABIInfo) const {
   // Check to see if we have an exact match and remember the best match we see.
   int BestMatchIdx = -1;
+  int LargestInt = -1;
   for (unsigned i = 0, e = Alignments.size(); i != e; ++i) {
     if (Alignments[i].AlignType == AlignType &&
         Alignments[i].TypeBitWidth == BitWidth)
@@ -271,14 +272,30 @@
             Alignments[BestMatchIdx].TypeBitWidth < BitWidth)
           BestMatchIdx = i;
       }
+    } else if (AlignType == INTEGER_ALIGN && 
+               Alignments[i].AlignType == INTEGER_ALIGN) {
+      // The "best match" for integers is the smallest size that is larger than
+      // the BitWidth requested.
+      if (Alignments[i].TypeBitWidth > BitWidth && (BestMatchIdx == -1 || 
+           Alignments[i].TypeBitWidth < Alignments[BestMatchIdx].TypeBitWidth))
+        BestMatchIdx = i;
+      // However, if there isn't one that's larger, then we must use the
+      // largest one we have (see below)
+      if (LargestInt == -1 || 
+          Alignments[i].TypeBitWidth > Alignments[LargestInt].TypeBitWidth)
+        LargestInt = i;
     }
-    
-    // FIXME: handle things like i37.
   }
 
+  // For integers, if we didn't find a best match, use the largest one found.
+  if (BestMatchIdx == -1)
+    BestMatchIdx = LargestInt;
+
   // Okay, we didn't find an exact solution.  Fall back here depending on what
   // is being looked for.
   assert(BestMatchIdx != -1 && "Didn't find alignment info for this datatype!");
+
+  // Since we got a "best match" index, just return it.
   return ABIInfo ? Alignments[BestMatchIdx].ABIAlign
                  : Alignments[BestMatchIdx].PrefAlign;
 }
@@ -407,8 +424,14 @@
       return 4;
     } else if (BitWidth <= 64) {
       return 8;
-    } else
-      assert(0 && "Integer types > 64 bits not supported.");
+    } else {
+      // The size of this > 64 bit type is chosen as a multiple of the
+      // preferred alignment of the largest "native" size the target supports. 
+      // We first obtain the the alignment info for this type and then compute
+      // the next largest multiple of that size.
+      uint64_t size = getAlignmentInfo(INTEGER_ALIGN, BitWidth, false) * 8;
+      return (((BitWidth / (size)) + (BitWidth % size != 0)) * size) / 8;
+    }
     break;
   }
   case Type::VoidTyID: